How to Say "One O'clock" in Spanish

la una

/la una/from spelling rulesfeminine

One o'clock in Spanish is la una.

la una is used to denote the start of the second hour.

Meaning: the start of the second hour (noun)

Which one should you use?

While la una is singular, all subsequent hours in Spanish use the plural article las, such as las dos for two o'clock.

To say 'at one o'clock', use the preposition a followed by the singular feminine article la to form a la una.

/la una/

Avoid using the masculine form el uno to refer to the time. Because the word for hour (hora) is feminine, you must use the feminine la una.

In some Spanish-speaking cultures, if someone is arriving a la una, they may actually arrive slightly later than the clock strikes one, as punctuality standards vary by region.
While la una is used for the clock, the masculine el uno is the correct form when referring to the number one in other contexts, such as a bus line or a specific date.
The word una shares its ancient Indo-European roots with the English word 'one', as both stem from a common source meaning 'single' or 'only'.

Me fui a dormir a la una.
I went to sleep at one o'clock.
This sentence shows how to express the time you went to sleep using la una.
Tatoeba #4998764 by don_ramon, translation #10072565 by espamatics
Me fui a la cama a la una.
I went to bed at one o'clock.
This sentence demonstrates using la una to say when you went to bed.
Tatoeba #2181152 by Shishir, translation #252455 by CK
Es la una.
It's one o'clock.
This sentence shows how to state the current time with la una.
Tatoeba #875816 by alexmarcelo, translation #618980 by Eldad

Javier and Elena are planning a lunch meeting.

Sources

Wiktionary, “one o'clock” translations, CC BY-SA 4.0, dump of 2026-09-26.
IPA marked “from spelling rules” is derived from standard Spanish spelling, where Wiktionary gives none.
Word origins: Wiktionary entries la, una, CC BY-SA 4.0.
Example sentences: Tatoeba CC BY 2.0 FR.

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